Due to Insanity (2015)

A found footage documentary that starts of with three friends, Ryan Halasz, Lee Milby and Mark Dukes, who discovered an abandoned insane asylum in New Jersey is being demolished to build a park. Ryan and Lee decide to go take footage and picture of what remains while Lee's boyfriend Mark stays behind. When they come back strange and unexplainable things start to happen like something is following them. Ryan starts to complaining of horrible nightmares while Lee goes into a downward spiral of madness. Lee then goes missing and Ryan and Mark decide to go back into the insane asylum tunnels in search of her but what they find is far beyond what they've ever imagined.